She's the top student at Starlight Academy, as well being the number one idol and starlight queen at Starlight Academy. Mizuki is the role-model of all idols, thus being admired by just about everyone especially Ichigo. She started off as an elementary model then mysteriously disappeared from the public for a whole year and came back as a top idol in Starlight Academy. During that time, she did intensive training and pushed herself to work her hardest because of her lack of ability. Mizuki doesn't show her hard-working side to many people and is thought of as a genius. As of Episode 28, she has her own brand designed after her image, Love Queen.

In episode 33 she announced that she was selecting two members for her new idol unit, Tristar. In the end, she selected Kaede and Ran. Ran later quits to join her friends unit, Soleil. In Ran's place, Mizuki selected Yurika. However, short after that the three units: Tristar, Soleil and Powapowa-Puririn (except Shion) merged into STAR☆ANIS.

In episode 50 Mizuki left Starlight Academy to work as the background adviser of Dream Academy, a rival school for idols. She later returns to the idol world in episode 75 with her new brand, Love Moonrise and her own agency known as Moonlight Office. Mizuki also revealed having started a unit, WM with Mikuru.

In Episode 86 the Aikatsu8 competition was announced, in which fans will show their support for their favorite idols and vote for them. Independent idols like Mizuki and Mikuru could also participate and they both would eventually become members of Aikatsu8 together with Seira, Otome, Sora, Maria, Yurika and Ichigo.

Mizuki was inspired to become an idol after seeing the legendary top idol unit Masquerade perform so after Aikatsu8 her goal became to surpass them by September. In episode 93 the Twinkle Star Cup was announced. The Twinkle Star cup is new a group competition founded by WM to challenge a group made up of one person from Starlight Academy and one person from Dream Academy. The reason behind the competition was so that Mizuki could finally fulfill her dream of surpassing Masquerade and to do so WM needed the "ultimate rival" which lead to the formation of Ichigo and Seira unit 2wingS.

She finally loses as WM to 2wingS in episode 100 but fulfills her dream of becoming a legendary idol like Masquerade. Mizuki tells Ichigo her plans to retire because she has fulfilled her goals and shortly after that Ichigo takes the number one Aikatsu Ranking spot beating her rival Mizuki.